1. Field of the Invention
The invention relates to methods, systems, devices and components for treating and reusing water in smaller venues. Small venues are, for example residential and small business. The invention relates more specifically to modularizable systems, components and methods for treating water available residentially for reuse and/or irrigation. Water sources suitable for the invention include blue water, black water, gray water, and water obtained through natural sources (such as rainfall, storm water runoff, and the like).
2. Description of the Background
With our increasing awareness of environmental issues, such as global warming, a need has been recognized for ways to preserve and efficiently use our natural resources. Large focus and effort has been placed on reduction of dependence on fossil fuel for energy. However, the importance of the limited supply of another critical resource has remained largely underappreciated. That resource is water.
It is estimated greater than 75% of the earth's surface is covered in water, however, only a small fraction of that water is drinkable or usable without treatment. Over 96% of water is ocean, seas and bays. Of the 4% of fresh water, 68.7% is trapped in ice caps, glaciers and permanent snow. (See, earthobservatory.nasa.gov) For example, salt water, which represents the vast majority of water, requires desalination before it is can be used for drinking or other purposes. See, US Pub 20060144789 to Cath for System and Methods for Purification of Liquids; 20060076294 to Sirkar for Devices and Methods Using Direct Contact Membrane Distillation and Vacuum Membrane Distillation; 20060076226 to Marcellus for Machine for desalinating salt water, brine water and impure water and the process for making same and a plant for making same; 20050189209 to Craven for Fresh Water Extraction Device. The desalination process requires a considerable amount of energy to accomplish. According to the California Coastal Commission, the cost of desalination ranges from 2,500-15,000 kWh/AF (kilowatt hour per acre foot). (See, http://www.coastal.ca.gov/desalrpt/dchap1.html).
Once water has been used in a residential and/or commercial environment, the resulting water can require elaborate, energy consuming, treatment before it is useable and/or reusable. Even lake and stream water can carry pathogens capable of making humans sick and therefore treatment and/or processing of the water to make it safe for human consumption is appropriate.
The typical wastewater stream contains both carbonaceous compounds and nitrogenous compounds (generally present as NH4+) exerting an oxygen demand and measured as a biological oxygen demand (BOD). BOD is a chemical procedure for determining how fast biological organisms use oxygen (through degradation of organic material) in a body of water. It is used in water quality management and assessment, ecology and environmental science. A BOD5 test measures the rate of oxygen update by micro-organisms in a sample of water at a temperature of 20° C. and over an elapsed period of five days in the dark.
In many areas compliance with water pollution control laws requires that wastewater treatment objectives consider the removal of both nitrogen and phosphorus in addition to the normal reduction of carbonaceous compounds and suspended solids. Phosphorus and nitrogen-containing compounds are essential nutrients for cellular growth. As such, continuous release of phosphorous and nitrogen containing water into natural receiving waters such as rivers and streams has resulted in progressive fertilization and eutrophication, thereby creating ubiquitous blooms of aquatic vegetation. This, in turn, has endangered aquatic life and caused a gradual degradation of the quality and esthetics of the water. Since the ultimate growth of these aquatic blooms depends on nutrient availability, reduction in the levels of phosphorus and nitrogeneous compounds would limit such undesirable growth.
Recent demands from governmental agencies are requiring improved purification of their waste water. Among others there are focus on organic compounds, phosphorous compounds and nitrogen containing compounds. The phosphorous compounds are often removed by an oxidative precipitation in which chemicals are added to the waste water and oxidize the phosphorous compounds to phosphates which are precipitated as sparingly soluble salts. The phosphorous compounds are normally either precipitated in a separate tank or in the septic tank
Furthermore, many countries in the world have serious health consequences from inadequate access to clean water and/or sufficient water for bathing and cleaning. Efforts have been taken on the part of NGOs such as Rotary International to address the need to increase access to reliable and safe water (See, http://www.rotaryorg/aboutrotary/president/boyd/water.html). In developing countries, part of the problem stems from the inaccessibility to municipal infrastructure providing access within the residential setting to blue water (i.e., water that is safe and useful for cooking, cleaning, bathing, and drinking). However, even in the United States and Europe there is an increasing awareness that regardless of how well designed the municipal infrastructure, access to water, and its limited availability in some regions, has far reaching impact on the community and the economy. In the U.S., it was recently reported that Las Vegas, one of the fastest growing metropolitan areas in the United States, is predicted to run out of water by 2016.
Typically, in the United States, many homes are connected to a municipal water source that provides an incoming stream of water, referred to as “blue water.” The U.S. Environmental Protection Agency (USEPA) sets the standard for water by enforces federal clean water and safe drinking water laws enforcing federal clean water and safe drinking water laws. There is no such thing as naturally pure water. In nature, all water contains some impurities. As water flows in streams, sits in lakes, and filters through layers of soil and rock in the ground, it dissolves or absorbs the substances that it touches. Some of these substances are harmless. In fact, some people prefer mineral water precisely because minerals give it an appealing taste. However, at certain levels minerals, just like man-made chemicals, are considered contaminants that can make water unpalatable or even unsafe.
Some contaminants come from erosion of natural rock formations. Other contaminants are substances discharged from factories, applied to farmlands, or used by consumers in their homes and yards. Sources of contaminants might be in your neighborhood or might be many miles away. Your local water quality report tells which contaminants are in your drinking water, the levels at which they were found, and the actual or likely source of each contaminant.
Some ground water systems have established wellhead protection programs to prevent substances from contaminating their wells. Similarly, some surface water systems protect the watershed around their reservoir to prevent contamination. Right now, states and water suppliers are working systematically to assess every source of drinking water and to identify potential sources of contaminants. This process will help communities to protect their drinking water supplies from contamination, and a summary of the results will be in future water quality reports.
Blue water is suitable for a variety of household uses and, because of the manner in which homes and business are plumbed, is used for applications that do not require the quality of blue water, e.g. watering the lawn, flushing toilets, etc. As water is used in a typical household, different qualities of water come out. Three qualities of water typically exit the system intermingled into either a municipal sewage system or a septic system. These three types include: blue water, e.g. where a tap of incoming blue water is run until it gets hot before pulling the stopper in the tub; gray water, e.g., water from the laundry, shower, bathroom sink, etc. that might have some impurities; and black water, e.g. water from the kitchen sink, dishwasher, and toilet. According to the USEPA, on average in the United States, residences use 400 gallons of blue water per day, and about 30% is devoted to outdoor use, such as watering the lawns. Some experts estimate than more than 50% of commercial and residential irrigation water goes to waste due to evaporation, runoff; or over-watering. For purposes of illustration FIG. 1 illustrates a typical residential water usage set-up.
Many of the currently available systems are directed to commercial or municipal sized water treatment facilities. For example, U.S. Pat. No. 3,764,523 to Stankewich Jr. for Nitrification of BOD-Containing Water is directed to a method for removing both carbon and nitrogen food from BOD-containing water by biochemical oxidation using oxygen gas in the presence of activated sludge.
Other efforts have been made to promote awareness of water as a resource and at least make a crude effort to re-use gray water for landscape usage. For example, Art Ludwig's Create an Oasis with Greywater: Choosing, Building and Using Greywater Systems (4th Ed. February 2006), discusses a variety of ways to save fresh (blue) water and irrigate with wash water. New Water in Australia has developed the Aqua Reviva system, for treating and recycling household graywater, and Rain Reviva system, for collecting and storing rainwater under a house (see, www.newwater.com.au). See, PCT Publication WO 2005/095287 to New Water Corporation for Water Treatment. The Aqua Reviva system comprises a collection cell to balance out variation and composition of gray water over the day, with an automatic overflow to the sewer. Composite gray water is then pumped through a hair and lint trap to a treatment cell where biological treatment, together with chemical and physical removal processes take place. The treated effluent is then disinfected via a mild bromine disinfection process and held a minimum of 30 minutes. Thereafter the effluent passes to a reuse cell which is sized to suite a household's reuse requirements. The treatment cell has three replaceable cartridges each capable of treating up to 235 liter/day, with a total capacity of 700 liter/day. Another system developed by Oasis ClearWater New Zealand is the Clearwater Series 2000 (see, www.oasisclearwater.co.nz). The ClearWater system is not a septic tank. It is an aerated wastewater treatment system comprising five stages of treatment. Liquid flows through the system by hydraulic disbursement. The wastewater first enters a pretreatment, settlement chamber. From there it flows into a secondary settlement chamber. From the secondary settlement chamber it passes through a filter where biological and mechanical filtration occurs. From there it passes to a central aeration chamber and then to a clarifier unit. Still another system for aerated wastewater treatment has been developed by Aqua-nova in Australia (see, www.aquanova.com.au). The Aqua-nova system is also a wastewater treatment process. Yet another system is developed by BioKube in Denmark (see, www. Biokube.com). The BioKube system provides for biological cleaning of sewage water to create water that is reusable for irrigation. The BioKube system breaks down hydrogen sulphide in a pre-settlement tank, prior to pumping the wastewater into a cleaning tank. See also, U.S. Patent Publication 2004/0173524 to Hedegaard for Method of Biologically Purifying Waste Water and a Plant Preferably a Mini Purification Plant to be Used by the Method.